Chemistry College (Need to know!) - GK, Thursday, June 11, 2009 at 5:43pm

Your signs on the right side are reversed. Bond breaking is endothermic and bond formation is exothermic. Some bond formations are endothermic (i.e. hydrogen bonding) that must be taken into account in conjunction with hydration which is also bond formation.
∆H(soln) = |∆H(lattice)| - ∆H(solute-solvent)

Chemistry College (Need to know!) - Ben, Sunday, June 14, 2009 at 4:30pm

How is this Possible GK.
Everywhere I have looked, including mark schemes and chemistry websites dH(solution) is worked out via this equation: